Sounds like you're overlooking a different issue. Fuses had better blow, not melt from over-current, otherwise, what good are they? Look at the terminals in the fuse box to see if they are blackened or corroded. Either of those things will cause heat to build up when current is flowing through them. THAT is what can cause plastic things to melt. Of course that's if the correct size fuses are in place.
To repair melted fuse boxes and switch connectors, you have to cut the overheated terminals out and replace them individually, and replace usually about 4" of the wires that have become hardened. All of the splices and terminals should be soldered and sealed with heat-shrink tubing. Never rely on twisting wires together and covering them with electrical tape.
Thursday, July 16th, 2020 AT 6:16 PM